Prion diseases are 100 percent fatal, there is no treatment available, and cannot be diagnosed prior to the occurrence of symptoms. There is a public health need and an enormous market for a screening test that can help protect the blood supply, screen live animals, and ensure food safety. We propose to develop and validate an innovative, highly sensitive screening method for the detection of the infectious prion protein in the blood of humans and animals. We have selected an amplification-boosted analytical method, immuno-polymerase chain reaction (I-PCR) that utilizes an amplifiable DNA-label coupled to a specific antibody, and combines serologic and molecular diagnostic potentials to amplify micro quantities of protein to detectable levels; the method's unparalleled sensitivity in the sub-femtogram range meets the criterion proposed for detection of prion in blood. Recombinant phage antibodies will be produced and used as specific reagents. Preliminary results have shown proof of concept that IPCR method has the needed sensitivity. The strengths include: (1) a scientific group with expertise in diagnostics and product development, (2) the selection of a highly sensitive analytical approach and novel detection probes, and (3) a strong business partner having expertise in translating prototype assays into sensitive, specific, and reproducible products. PROPOSED COMMERCIAL APPLICATION: The ability to detect prion diseases is significant for ensuring the safety of the blood supply and eliminating the possibility of acquiring disease through the ingestion of certain foods such as beef and beef brains. The sensitive I-PCR assay for Prion will also prevent well-documented cases of iatrogenic transmission through the use of human growth hormone, dura mater, organ transplantation, and the likelihood of transmission through the use of surgical treatment. Commercial applications also extend to the epidemiologic surveillance of human and animal healthy programs, as well as food, drug and vaccine industries.